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Fencer Intel
medium 5.9

CVE-2026-33261 json

Null pointer accces in aggressive NSEC(3) cache

published 6mo ago modified 14d ago also EUVD-2026-24727

cvss
5.9
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 15%
public exploits
0
none known

Summary

A zone transition from NSEC to NSEC3 might trigger an internal inconsistency and cause a denial of service.

Patch / fix

  • PowerDNS Recursor 5.2.9, 5.3.6, 5.4.1
  • pdns-recursor Debian 13 5.2.9-0+deb13u1
  • pdns-recursor Debian 14 5.4.1-1

debian advisories DEBIAN-CVE-2026-33261

  • pdns-recursor Alpine 3.23 5.3.6-r0
  • pdns-recursor Alpine 3.24 5.4.1-r0

alpine advisories ALPINE-CVE-2026-33261

Alpine secdb © Alpine Linux, from https://secdb.alpinelinux.org via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

Is CVE-2026-33261 in your stack? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

Check with Fencer

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-33261 updated cvss 7.5

pdns-recursor: NULL pointer access in aggressive NSEC(3) cache

  • Red Hat All currently supported Red Hat products
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
6mo ago

Exploit prediction

0.24% chance of exploitation in the next 30 days, higher than 15% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by version score vector
CNA 3.1 5.9 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected products

  • PowerDNS Recursor

Classification

Weakness
  • CWE-353 Missing Support for Integrity Check

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.